Damper regulator



Sept. 6, 1932 G, A KQHUT 1,875,616

DAMPER REGULATOR Filed May 26, 1950 4 Sheets-Sheet l @a0/yew?? l v Sept. 6,1 1932.

G. A. KoHouT DAMPER REGULATOR Filed May 26, 1930 4 Sheets-SheerI 2 lll i w3 JZ l-l Sept. 6, 1932. G. A. KoHoUT 1,875,616

DAMPER REGULATOR Filed May 26, 1930 4 Sheets-Sheet 5 Sept. 6, 1932. G. A. KoHouT DAMPER REGULATOR Filed May 26. 1930 4 Sheets-Sheet 4 Patented Slept'. 6', 1932 UNITED VSTATES' GEQRGE A. KoHoUT, ory on'roasoiLLINoI's Y1mi/.Irun nneunafron" Y Application medmay 2e, 1930. -seriaino. 455,715; V

My invention relates to damper regulating devices for furnaces and more particularly to an automatic damper opening and closing device adapted to operate in conjunction with the fuel feeding mechanism of the furnace to open the damper and close it at the proper time. This application is an improvement over the structure disclosed in Vmy prior application Serial No. 857,708, ile'd April' 24, 1929.

Itis the principal purpose of this invention to provide an improved mechanism whereby to control by purely mechanical action the operation of the damper in response to stop- 15 ping and starting of the fuel feeding'means.

Other and more specific objects of the invention will appearastthe description proceeds when` taken in connection with `the accompanying drawings. It is tobe understood,

. however, thatthe drawings and description are illustrative only and are not to be taken as limiting the invention except in so far as it is limited by the claims.

Vlnthe drawings-- Fig. 1 is a diagrammatic view showing the connections of the damper and the fuel feeding shaft to my improved means for controlling the operation of the "damper,

Fig. 2 is a section through the pockets containing the control lmechanism illustrating the position when the damper is closed;

Fig. 3 is a similar section illustratinganother position when the damper is open;

1 Figl is a small sectional view taken on the line L -l of Fig. 2; Fig. 5 is a section on the line 5-5 'of Fig. 2; f i

Fig. 6 is a section taken approximately on the line 6 6 of Fig. 3 showing the mechanism just as it has been released to permit the damper to close ,j

\ Fig. 7 is a front view illustrating the drive shaft operating mechanism as shown in my prior application;

Fig. 8 is a diagrammatic viewshowing the wiring` connections for the drive shaft oper- Aatingzinechanism.; and Y Fig. 9 is a fragmentary section on line 9-.-9 of Fig. 7. I

Referring now in detail to, the drawings,

the numeral 1 0 indicates a crank arm on the main fuel feeding shaft ofthe stokerfwhich arm operates as illustrated in my prior appli# cation backend forth through a considerable angle and is so y controlled as to stop atthe .55 top of its movement range when thepower is cutoff` from the main fuelfeedingfshaft'. The main fuel feeding vshaft has in addi-` f tion .tovcrankarm 19 a crank arm 61 ,thereon carrying a pin 62 adapted to engage button 63 of switch `64C` so as to open thel circuit through this switch when crank arm 10is yin its raised position as shown.V Switch .Gais a part of the control of motor 6,5 which is. connected by means ofreduction gearing' toc'ranl;

V66 as described in my prior. application.

Crank 66is connected by link 67and arm 68 to shaft 60 forrockingthe shaft. -l The operationin-stopping motor insu'ch fashion as to leave crank arm 10 inraisedfposition may Vbehest understood by reference to Fig. 8, the wiring diagram. Gne side of motor 65 is lconnecteddirectly to onesideof a source of current, but the .other side of the.` motor is connected to the source of current 75 through switch 6a and a switch 69 in parall'el; Now lwhen .the machine is running,` switch`69 is closedan d switch 6a is periodicallyopened when pin 6 2 pressesdown button 6 3. So long as 69 is closed, the motor `still receives currenteven though 64 is periodically opened. `When 69 is `opened to stop the kmotor, the

motorcontinues to receive current through .64 and drive the shaft GOuntil crank armjlO reaches its kraised position as shown `inl Fig.- `55 9 when pin 62 opens switch 641: andthe motor stops. In this manner crank arm 10 is caused tostop in raisedposition at all times. {The crank 10 is connected by means of `rod l1 1v which has a sliding rconnection therewith as 9.0 illustrated by Fig. 1 to a lever arm 12. This ,lever arm is pivoted"on a mainshaft 13 with'- in thecasing ofthe control boX and has one end connected by means of the link 14e to the piston rod 15 of a suitable dash pot 16. This `9 5 dash pothas a by-pass suitably controlled by the valve shown 'at 18 so that the rate of travel of the piston 15 Vmay be adjusted'by ychanging the lsetting of the valve 18.V Lever arm 12has `a laterally extending lug 20 eX- :100

tending over a second lever arm 21 also pivoted on the shaft 13. Spring 22, the tension of which may be adjusted by means of the bolt 23 and nut 24, is secured to the lever arm 12 by means of the lug 25 so as Vto tend to pull the arm 12 into the position shown in Fig. 2 where further movementvdue to the pull of the spring22 is prevented by meansv of the stop 26 mounted on the casing.

The lever arm 21 is connected at 27 to a flexible member 28 usually inthe form of a cable having means at 29 in the form of chain links for adjusting its length and having hand grip member 30 provided with notches at 31 for further quick adjustment or detachment. The'flexible member 28 connects to one end 32 of bell crank 33 mounted on the damperV shaft. The 'other end of the bell crank 33 has a weight 34 suspended therefrom which-weight tends to'holdthe damper in its closed position. v Y

The lever arm 21 has a link 35 at the end 'opposite the connection 27 which link connects to piston rod 36 of a second dash pot 37 having the by-pass 38 controlled by valve 39. The adjustable stop 40 screw-threaded in the casing limits the movement of arm 21 upwardly jby weight 34 and flexible member 28.

Now each time the crank 10 moves to lower position it pulls the lever arm 12 down with it. On the return movement, however, of the crank 10 kthe dash pot 16 retards the upward movement of lever arm 12 so that it does not rise very far until crank 10 again pulls it down. When the lever arm 12 is'pulled down intoitsY lower position by crank 10, it carries with it by means of the lug 2O lever arm 21. Lever arm 21 has a latch 41 pivoted thereon and yieldingly held in the position shown in Fig. 2 by means of the lspring 42 and stop 43. This latch when the arm 21 is pulled down hooks over the tooth 44 of'holding pawl 45 which pawl is mounted on the frame 46 secured to the side of the casing and is yieldingly held in thel position shown in Fig. 2 by means of the spring 47. The pawl has a rearwardly extending arm 48 which when the arm 12 is in lowered position for instance as shown in Fig. 3 is held by means of a second pawl 49 having the shoulder 50 which engages under the free end of the arm 48. A suitable spring indicated at 51 normally tends to move the pawl 49 into the position shown in Fig. 3. lPawl 49 valso has a. lever' arm 52 which is adapted to be engaged by depending link 53 pivoted at 54 to the lever arm 12.

Having once been latched down by means of the latch 41and tooth 44, lever arm 21 will Y be held in the lowermost position with the damper open so long as the fuel feeding shaft on which the crank 10 is mounted continues Vto operate. However, when the crank 10 isA by-pass of the dash pot 16 which is filled with 'i l45. Y l/Vhen this happens, the pawl 45 is free to turn against the tension of the spring 47 so as to permit tooth 44 to move upwardly and disengage from the latch 41, arm 21 being pulled upwardly by the weight 34 at all times.

Release of the latch 41 permits the arm 21 to move upwardly at a ratey governed bythe dash pot 37 luntil the arm 21 strikes the stop 40 where the arm will stay until such further time as the fuel feeding operation again begins when the` arm 21 will he pulled down and latched in the manner hereinbefore described so as toopen the damper during the fuel feeding interval. The shaft 13 also performs another function as illustrated in my prior` application, namely that of opening the over-lire doors of the furnace and opening the steam supply jet when the damper-is open. In the present device, this is accomplishedby means ofthe link 55 connected by a suitable arm 56`to shaft 13. Shaft 13 is .free to rotate in its bearings in the casing, and the arms 12vand 21 are rotatably mounted on this shaft. arm 21, however, has a lateral extension at V57 which abuts the bearingfon the casing for the shaft and which eXtendsonly part way around the shaft. Pin58 extends through the shaft in line with this abutment andis so positioned with respect to the abutment that lever arm 21 mustv swing down substantially into horizontal position before the abutment will engage the pin and rotate the shaft 13. Thereafter on further downward movement of the arm 21 towardV the position shown in Fig. 3, shaft 13 will be turned in the direction of the arrow shown in Fig. 1 to raise the link 55 which is in turn operatively connected-as shown in my prior application hereinbefore referred to--so as to effect the opening of the steam supply lines and the over-fire air supply doors. raised position, the first'operation is during the lower half of its movement suflicient to allow shaft 13 to turn and closethe over-fire doors and steam supply line. The adjusting screw 40 is preferably made so that its lower limit will lonly hold th-e arm 21 down tohori- Zontal position. Thus it is possible to coin'- pletely control the over-fire doors and steam The hub ofk 1n the return of the arml 21 to its ill-5 jet even though the damper isleft partly open to allow gas to escape from the furnace.v

From the above description, it will be seen that I have .provided a comparatively simple yet rugged construction whereby the opening and closing of the damper of a furnace may be automatically accomplished from a drive shaft operating in conjunction with the fuel feeding means. This construction hasgreat advantages in that the adjustments at the time period between the shutting offof the fuel feeding means and the closing of the damper may be varied through a wide range by merely adjusting the valve on the dash 1. In damper control mechanism, a damper,-

means for maintaining the damper in open position while a drive element is operating and moving it into closed position when the drive element stops comprising a shaft, a pair of lever arms thereon one having connection with the damper and the other with the drive element, means for causing said arms to move in unison to open the damper, latch means for latching the damper connected arm in position on completion of the opening movement, and means operated by the other lever arm upon stopping of the drive means to release said latch means, said damper having means tending to move it to closed position.

2. A damper control mechanism for furnaces comprising a damper, means yieldingly urging said damper into closed position, a drive element, means connecting said drive element and damper operating to open said damper and retain it open during operation of said drive element, and release means becoming operative upon stopping said drive element to release said damper whereby said first named means may close the damper, said connecting means including a lever arm connected to said damper so as to be held up when the damper is closed, means including a second arm pivoted on the same axis as said lever arm and operated by said drive element for moving said arm down, and latch means for retaining said arm in lower position, said release means operating said latch means.

3. A damper control mechanism for furnaces comprising a damper, means yieldingly urging said damper into closed position, a drive element, means connecting said drive element and damper operating to open said damper and retain it open during operation of said drive element, and release means becoming operative upon stopping said drive element to release said damper whereby said first named means may close the damper, said connecting means including a lever arm connected to said damper s0 as to be held up when the damper is closed, means operated by said drive element for moving said arm down, and latch means for retaining saidarm in lower position, and means for variably retarding the closing of said damper.

A4. "A ydamperfcontrol mechanism `for {fur-'f nacesy comprising a damper, means -yieldingly' urging said damper into'l closed position,1a drive element, lmeans connecting said drive element and damperoperating to open lsaid damper and retain it open during operation" v ofjsaid drive element, and lrelease-means becomingV operativeupon stopping said drive` v element'to'release said damper whereby said first named means may close the damper, said, connecting means including'a lever arm'v con-` nected to said damper `so as to beheld up when the ldamper is closed, meansjoperated by said` drive element'y for moving said arm down., and latch meansfor retaining said arm in lower position, 'and means forv variably retarding the closing ofsaid damper compris` ing a dashpotl connected with said lever 5. 'A damper control mechanism `for Vfur` naces comprising a damper, means yieldingly urging said dainperlint-oclosed position, a

drive' element,'means `connecting said drive element'and damper'operating to'open said damper and retain it open during operation of said drive element, and release meansbe coming operative uponstopping'said drive element torelease said damper whereby said rst named means mayclose the. damper, said connecting meansincluding a lever arm. connected to said dampersoas'to be held up when the damper is closed, meansioperat'ed by said drive element for moving said arm down, and latch means' for `retaining 'said arm in lower position, said'release means `,oper-- ating said latch'means, and means forvaryf.

ving thev period of time after saidud'riving element stops before/said release means releases the latchlV A damper control mechanism orfilir-` naces comprising a damper, means" yieldingly urging said `damper intoy closed position, a" drive element,` means connecting said "drive element and damper operating to open said damper and retain itV open during operationv offsaid drive element, and release means be!4 coming operative'upon stopping said drive element to release said damper whereby said lirst named means may close the damper, said connecting means including lever arm connected to said damperso as tobbeheld 'up when the damper is closed, means operated by said drive element for moving said arm down, and latch means for retaining said arm in lowerposition, said release means operat,. ing saidl'atch means, and means for varying theperiod of time after said driving element stopsbefore' said release meansreleases the latch comprising a dash pot associated with said release means.

7 A damper control mechanism for furmisl naces comprising a damper, means yieldingly damper and retain it open during operation of said drive element, and release means becoming operative upon stopping said drive element to release said damper whereby said first named means may close the damper, said connecting means including a lever'arm connected tosaid damper so kas tobe vheldup when the damper is closed, means operated by said drive element for moving said arm down, m and latch means for retaining vsaid arm in Y lower position, said release means operating said latch means, and means or'variably retarding the closing of, said damper. 8.--A damper control mechanism for furnacesjcomprising a damper, means yieldingly urging'said damper into closed position, a drive element, means connecting said ,drivel element and damper operating to openfsaid damper and retain it open during operation n of said drive element, andrelease means becoming operative upon stopping said drive element to release said damper whereby said first named means' may close the damper, said connecting` means including a lever arm n. connected to said damper so as tobe held up when thev damper is closed, means operated by said drive element for moving said arm down, and latchA means for retaining said arm in lower position, said release means operatw ing said latch imeans,l and means -for varyingy the period of time after said driving element stops before said release means releases the latch, and means for variably retarding the closing of said damper.' v 95, yA damper control mechanism for furnaces comprising a damper, means yieldingly urging *said ydamper into closedvposition, a drive element, means connecting said drive element and damper operating to open said i. damper and retain it open during operation of said drive element, and release means be-V coming operative upon stopping said drive element to release said damper whereby said Y first named means may close the damper, said s connecting in eans including a lever arm connected to said damper so as to be held up when the damper is closed, means operated by said drive element for movingsaid arm down,and latch means for retaining' said arm 50 in lower position, said release means operating saidlatch means, and means for variably lretarding the closing` ofrsaid damper comprising a dash pot connected with said lever arm. Y .55 In witness whereof, I hereunto subscribe my name this 20th day of May, A. D. 19730. GEORGE A. KOHOUT. 

